I'll check the weather forecast.
It'll be snowing. We're in Rochester.
Yes, but I can find out when it will be snowing.
It will snow the whole time we're in Rochester, just as it has all day every day we've been here so far. It doesn't actually matter when we arrive or leave. It will always be snowing.
Hmm. The internet agrees with you. It says 100% chance of precipitation through all the hours we might still be here. Okay, smartypants, how much snow will we get?
All of it. We're in Rochester.